JP2015131656A - Resin carrier board and manual transport method for article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin carrier board that is installed under an article to manually transport an article, and that makes a worker hardly slip while the article excellently slips, and is suitable to, especially, a polypropylene-made article.SOLUTION: A resin carrier board is manufactured by monolithic molding by an injection molding machine after first resin pellets prepared so as to contain 10-20 pts. by mass of silicone oil for 80-90 pts. by mass of base resin equal to or more than 98% by mass of polyacetal resin and second resin pellets made of polyacetal resin are mixed and agitated so that the content of the silicone oil is 3-4% by mass of the whole. On an upper surface, a plurality of ribs 20 of 1 μm or less in top-part surface roughness Ra are formed in parallel with one another. When used, resin carrier boards are laid successively having ribs in parallel with a conveyance direction, and a worker puts on shoes whose soles are made of urethane or rubber, and transports articles.

Description

  The present invention relates to a resin transport plate for assisting manual transportation of articles and a manual transportation method of articles.

  As an apparatus for assisting in manually transporting articles in a factory, a transport plate formed of a resin material has been proposed (Patent Documents 1 and 2). These devices can be installed at a lower cost than conventional roller conveyors.

  However, Patent Document 1 shows that polyamide, polyacetal, ABS, polycarbonate, or the like can be used as a resin material. However, when these materials are used alone, work for carrying heavy objects is performed. The burden on the person was great.

Patent Document 2 discloses a technique of applying a sliding agent in order to improve sliding properties in addition to using polyacetal as a resin material. However, when a sliding agent is applied, there is a problem that the worker on the transport plate slips and the force does not enter.

For this reason, there has been a demand for an article made of a resin that has a higher slidability than the case of using a resin material alone as an article and that makes it difficult for an operator to slip.

JP 2008-260629 A JP 2013-151322 A

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a resin-made transport plate that slides well and is hard for an operator to slip. Moreover, it aims at providing the manual conveyance method of the articles | goods using the resin conveyance board.

  Usually, articles to be transported in factories are loaded on resin pallets. The material of the pallet is mostly durable and inexpensive polypropylene. However, although there are data showing the coefficient of static friction with iron for various resin materials and resin additives, there was almost no data showing the coefficient of static friction with polypropylene. For this reason, in order to search for a resin material having a small static friction coefficient with respect to polypropylene, the inventor has completed the present invention as a result of intensive experiments.

That is, the present invention is a resin-made transport plate that is installed under an article when the article is manually transported, and is based on 96 to 97 parts by mass of the base resin containing 98% by mass or more of polyacetal resin. It contains 4 parts by mass and is integrally molded by injection molding.

As a result of the inventor's experiment, it was confirmed that by blending the silicone oil with the polyacetal resin at such a ratio, the slidability with respect to polypropylene is extremely improved. Moreover, it was confirmed that it was hard to slip with respect to the urethane or rubber normally used for the sole of safety shoes.

The present invention also provides a first resin pellet prepared in advance so as to contain 10 to 20 parts by mass of silicone oil with respect to 80 to 90 parts by mass of a base resin of 98% by mass or more of polyacetal resin, and a polyacetal resin. It is desirable that the resin pellets of No. 2 are mixed and stirred so that the content of the silicone oil is 3 to 4% by mass, and then integrally molded by an injection molding machine.

Silicone oil has a problem of low compatibility with polyacetal resin and is difficult to disperse throughout the molded product. For this reason, silicone oil is often unevenly distributed in the skin layer of the resin transport plate surface layer. When silicone oil is unevenly distributed on the skin layer of the resin transport plate, the friction and wear characteristics are good when sliding on the skin layer, but the sliding surface reaches the crystal layer inside the resin transport plate due to the progress of wear. In this case, the friction and wear characteristics are extremely lowered. In addition, the bonding force between the skin layer of the resin transport plate surface layer in which a large amount of silicone oil is present and the crystal layer inside the resin transport plate is weak, which may cause a peeling phenomenon. However, according to the present invention, since the silicone oil can be uniformly dispersed in the resin-made transport plate, high slidability can be maintained over a long period of time, and no peeling phenomenon occurs.

  Further, the resin transport plate of the present invention has a rectangular shape in plan view, and is a connecting portion for connecting the resin transport plates to each other, and has a dimensional allowance in consideration of expansion and contraction due to a temperature difference between summer and winter. It is desirable to provide the connection part which has.

In order to spread the resin-made transport plates in an orderly manner, it is convenient that the resin-made transport plates have a connecting portion for connecting the resin-made transport plates. This is because it becomes a guide when connecting linearly. Also, if the interval between the resin transport plates is opened, it is desirable to lay as close as possible because there is a possibility that the article is caught in the gap, but because polyacetal has a large change in shrinkage due to temperature, If it is laid in close contact with the cold season, it will float in summer. However, according to the present invention, when laying in the summer, as close as possible within the margin of the connecting portion, when laying in the winter, as far as possible within the margin of the connecting portion, It can be laid easily at appropriate intervals.
Moreover, the intensity | strength of connection can be raised by providing the connection part.

  Further, in the resin transport plate of the present invention, it is desirable that a plurality of ribs having a top surface roughness Ra of 1 μm or less are formed so as to be parallel to each other, and at least a part of the ribs is formed. The rib can be provided with a high portion and a low portion on the ridgeline. In addition, Ra (arithmetic average surface roughness) shall conform to JIS B0601: 2001.

  According to Coulomb's law of friction, the friction force does not depend on the apparent contact area. Therefore, it seems that the frictional force is not reduced even if the rib is provided. However, there are still various theories about the mechanism by which this law is established, and there is no unified clarification. According to the inventor's experiment, it has been confirmed that the frictional force is reduced by providing the rib. Further, although there are various theories on the relationship between the surface roughness of the contact surface and the friction coefficient, according to the inventor's experiment, the smoother the surface, the smaller the friction coefficient. If Ra is 1 μm or less, a very good sliding property is obtained. It has been confirmed that mobility can be obtained. Further, comparing the friction coefficient in the direction parallel to the rib and the friction coefficient in the direction perpendicular to the rib, it has been confirmed that the friction coefficient in the parallel direction is smaller. This is a difference that you can feel when you press it with your hand. However, it has been confirmed that the friction coefficient in the vertical direction can be reduced by providing a high portion and a bottom portion on the ridgeline of the rib.

  Further, in the manual transportation method for articles according to the present invention, the resin transport plates are connected and laid so that the ribs are parallel to the transport direction, and the articles are placed on the resin transport plates. Wears urethane or rubber shoes to carry articles.

As described above, the resin conveyance plate according to the present invention has a smaller coefficient of friction when conveying an article in a direction parallel to the direction of the rib than when conveying an article in a direction perpendicular to the direction of the rib. Therefore, according to the method of the present invention, the operator can carry the article with a lighter force. In addition, as described above, since the resin-made transport plate according to the present invention has a high coefficient of friction against urethane or rubber, it is easy for an operator to put power on the shoe sole wearing urethane or rubber shoes. is there.

  According to the present invention, the article can be transported with a light force, and the shoes are difficult to slip, so that the burden of work difference can be reduced.

It is a whole perspective view of the resin-made conveyance board which concerns on 1st embodiment. It is a top view of FIG. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is an enlarged view of the back side of the connection piece of the resin-made conveyance board of FIG. It is an enlarged view of the recessed part of the resin-made conveyance board of FIG. It is an enlarged view of a connection part when connecting the resin-made conveyance boards of FIG. It is a figure which shows the back side of FIG. It is explanatory drawing which shows the usage example of the resin-made conveyance board of FIG. It is a schematic diagram explaining the rib shape of the resin-made conveyance board which concerns on 2nd embodiment.

  Hereinafter, although the embodiment which embodies the resin-made conveyance board which is the present invention is described using a drawing, the technical scope of the present invention is not limited to this as a matter of course.

(First embodiment)
First, the structure of the resin conveyance board 1 which is 1st embodiment is demonstrated with reference to FIGS. As shown in FIGS. 1 to 4, the resin transport plate 1 is mainly composed of a flat base portion 10 and a plurality of ribs 20 erected on the upper surface of the base portion 10.
In the present embodiment, the ribs 20 are formed at intervals of 15 mm so as to be parallel to each other along the longitudinal direction of the base portion 10. The surface roughness Ra of the top portion of the rib 20 that is a contact surface with an article to be conveyed (not shown) is 1 μm or less.
Further, in the present embodiment, the base portion 10 has a width of 30 cm × a depth of 40 cm × a thickness of 3 mm, and a plurality of rounded square shapes are formed between the ribs 20 at equal intervals of 10 mm along the forming direction of the ribs 20. A hole 30 (a rounded square with a side of 10 mm) is formed. The hole 30 is not an essential element in the present invention.

  By providing the rib 20 in this manner, the slidability can be improved as compared with the case where the rib 20 is not provided. In addition, since the surface roughness Ra of the sliding surface is 1 μm or less, even better slidability can be obtained. Another reason for providing the rib 20 is that otherwise it is difficult to make the surface roughness Ra of the sliding surface 1 μm or less. This is because it is difficult to polish the mold unless the shape is linear. Furthermore, as a secondary effect, warping due to sinking can be controlled in a certain direction.

As shown in FIGS. 1, 2, and 5, a plurality (four in this example) of connecting pieces 41 are formed at appropriate intervals on the first end on the short side of the resin transfer plate 1. Further, as shown in FIG. 5, a cylindrical protrusion 41 a is formed on the connecting piece 41 toward the back surface side.
As shown in FIGS. 1, 2, and 6, a connecting piece 41 of another resinous conveying plate 1 is provided at a position corresponding to the connecting piece 41 at the second end on the short side of the resinous conveying plate 1. A recessed portion 42 that can be fitted is formed. Further, as shown in FIG. 6, the recess 42 is formed with a connection hole 42 a into which the protrusion 41 a of the connected connection piece 41 can be further fitted. The connecting hole 42a is a long hole and has a dimensional allowance in consideration of expansion and contraction due to a temperature difference between summer and winter.
In addition, the connection piece 41 and the recessed part 42 are equivalent to the connection part in this invention.

As shown in FIGS. 7 to 8, when connecting and laying the resin transport plate 1, when laying in the summer, when closely laying within the margin of the connecting hole 42 a, and laying in the winter Are separated as much as possible within the margin of the connecting hole 42a (FIGS. 7 to 8 show the case of laying in winter). As a result, the strength of the connection can be increased, and summer float can be prevented.

The resin transfer plate 1 contains 3 to 4 parts by mass of silicone oil with respect to 96 to 97 parts by mass of the base resin containing 98% by mass or more of polyacetal resin, and is integrally formed by injection molding.
More specifically, the resin transport plate 1 is a first resin pellet prepared in advance so as to contain 10 to 20 parts by mass of silicone oil with respect to 80 to 90 parts by mass of the base resin of 98% by mass or more of the polyacetal resin. And the second resin pellet made of polyacetal resin are mixed and stirred so that the content of silicone oil is 3 to 4% by mass of the whole, and then integrally molded by an injection molding machine.
The base resin of the first resin pellet is 98% by mass or more of polyacetal resin because melamine compound, hydrazine compound, urea compound, nitrogen compound, hindered phenol antioxidant, etc. are used as additives. This is because it may be used.

  In the present embodiment, a first resin pellet prepared in advance so as to contain 20 parts by mass of silicone oil with respect to 80 parts by mass of a base resin of 99% by mass or more of a polyacetal resin, and a second resin pellet made of a polyacetal resin, Was mixed and stirred so that the content of silicone oil was 3.6% by mass (the second resin pellet was 82 parts by mass with respect to 18 parts by mass of the first resin pellets), and then the injection molding machine was used. It is integrally molded.

Next, the result of having measured the static friction coefficient with respect to polypropylene by changing the silicone oil content of the resin transport plate 1 as appropriate will be described. As a method of changing the content rate of the silicone oil, it is performed only by changing the mixing ratio of the first resin pellet and the second resin pellet, and the other conditions are the same as in this embodiment ( The content of silicone oil in the first resin pellet is the same).
The purpose of this test was not to comply with JIS K 7125 because the purpose was to investigate how the static friction coefficient changes relatively when the silicone oil content is changed.

(1) Test pieces About 100 (resin transport plates a to f) in which the silicone oil content of the resin transport plate 1 and the resin transport plate 1 is changed (resin transport plates a to f), each of which is made as flat as possible. Each one with a high value was selected.
For polypropylene, a test piece of 100 mm × 100 mm × 5 mm was employed.
(2) Test method A polypropylene test piece is placed on the resin transport plate 1 and the resin transport plates a to f, and a weight of 2.7 kg having a smooth bottom surface is placed on the polypropylene test piece via a felt. And after leaving still for 15 second, the test piece was pulled with the fixed load and speed | rate via the spring, and the load (peak load) when the test piece started to move was measured. Each was measured five times, and the coefficient of static friction was determined from the average value.
(3) Test results Table 1 shows the test results.

  Thereby, when the content rate of silicone oil was 3-4%, it has confirmed that the friction coefficient with respect to a polypropylene became very small. Further, it was confirmed that the silicone oil content was the smallest when the content was 3.6%.

Next, with reference to FIG. 9, the conveyance method of the return box 60 (equivalent to articles | goods) using the resin-made transfer plates 1 is demonstrated.
In this description, a method will be described in which a product (not shown) manufactured on a line (not shown) in a factory is placed in a polypropylene return box 60 and conveyed to a shipping place.

First, the worker M performs an operation of laying a plurality of resin transfer plates 1 from the end point S of the line in the factory to the shipping place G. At this time, the ribs 20 are connected and laid through a connecting portion so as to be parallel to the transport direction, and are attached to the floor with a double-sided tape (not shown). Of course, this work may be performed by a person other than the worker M or may be performed in advance.
Next, the worker M places the return box 60 on the resin transport plate 1 near the end point S of the line in the factory, and puts the manufactured product into the return box 60. As shown in FIG. 9, a plurality of returnable boxes 60 may be stacked. Of course, this work may be performed by a person other than the worker M.
Next, the worker M wears shoes whose soles are made of urethane or rubber and pushes the return box 60 to carry it to the shipping place G. At the time of arrival at the shipping place G, the work is finished.

(Second embodiment)
Next, the resin conveyance board 2 which is 2nd embodiment of this invention is demonstrated using FIG. The resin transport plate 2 is different from the resin transport plate 1 only in that there are no rounded square holes 30 and connecting portions, and the rib 220 is different from the rib 20 in shape. Therefore, only the rib 220 will be described, and the description of other overlapping parts will be omitted. In the following description, members having the same or equivalent configuration as the resin transport plate 1 are denoted by the same reference numerals in the drawings.

The rib 220 of the resin transport plate 2 has a plurality of high portions 221 (the heights of all the high portions 221 are the same) and a plurality of low portions 222 on the ridgeline. That is, the sliding surface is only the high portion 221. By setting it as such a shape, compared with the rib 20, the slidability to the perpendicular direction of a rib can be improved.

The contents described above relate to an embodiment of the present invention, and do not mean that the present invention is limited to the above contents. For example, in the first embodiment, the connecting portion is provided only in the short direction, but it is needless to say that the connecting portion may also be provided in the longitudinal direction.
The numerical values (dimensions) described in the present embodiment are not limited to this, but are design matters determined by the weight, size, etc. of the product to be conveyed.

1 resin transport plate (first embodiment)
2-resin transport plate (second embodiment)
10 Base 20 Rib 30 Hole 41 Connection Piece 42 Recess 220 Rib

Claims (6)

It is a resin transport plate installed under the article when manually transporting the article,
A resin-made transport plate that contains 3 to 4 parts by mass of silicone oil and is integrally formed by injection molding with respect to 96 to 97 parts by mass of a base resin containing 98% by mass or more of polyacetal resin. It is a resin transport plate installed under the article when manually transporting the article,
First resin pellets prepared in advance so as to contain 10 to 20 parts by mass of silicone oil with respect to 80 to 90 parts by mass of base resin of 98% by mass or more of polyacetal resin, and second resin pellets made of polyacetal resin A resin transport plate integrally molded by an injection molding machine after mixing and stirring so that the silicone oil content is 3 to 4% by mass. The resin transport plate has a rectangular shape in plan view,
Furthermore, it is a connection part which connects the said resin-made conveyance boards, Comprising: The product made from resin of Claim 1 or 2 provided with the connection part which has the dimensional allowance which considered the expansion-contraction by the temperature difference between summer and winter Transport plate.   Furthermore, the resin conveyance board in any one of Claims 1-3 in which the some surface rib Ra whose top surface roughness Ra is 1 micrometer or less is formed in the upper surface so that each may become mutually parallel.   The resin conveyance board of Claim 4 with which the high part and the low part are provided in the ridgeline in at least one part rib among the said ribs. A method in which an operator manually transports an article,
The resin transport plate according to claim 4 or 5 is connected and laid so that the ribs are parallel to the transport direction, and an article is placed on the resin transport plate, and an operator has a shoe sole made of urethane or A method for manually transporting articles by carrying rubber shoes.

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